A break-off spout known in the prior art has a spout main body provided with a tube having a channel that passes through its center, the tip of the channel being closed by a break-off section that is formed integrally on the tip of the tube.
In addition, it is also know that, for hygiene purposes, a break-off spout is provided with a cover that covers the periphery of the tip side of the tube of the spout main body to prevent fingers from directly contacting the spout main body, and moreover that improves the convenience of the user by enabling the operation of removing the cover to be carried out at the same time as the operation of detaching the break-off section (for example, refer to Patent Documents 1 and 2).
Still further, it is also known that, in order to simplify production and assembly (for example, refer to Patent Document 3), the break-off spout has a cover which is integrated with the spout main body.
In known break-off spouts such as described in Patent Documents 1 and 2, the covers (cap 12 and cap 3) are parts that are distinct from the spout main bodies (opening 10 and spout 2), thereby adding to the number of parts and increasing the number of production and assembly steps. In addition, because these are constructions in which the covers (cap 12 and cap 3) are placed and secured onto the break-off sections (twist-off protrusion 18 and sealing member 15) and because force is consequently applied when putting on the covers (cap 12 and cap 3), the problem arises that the weakened sections (thin-walled portion 24 and thin-walled portion 16) may be damaged with a resulting loss of sealing performance.
Finally, if external force is applied to the covers (cap 12 and cap 3) during transport or storage, there is concern that force will be applied to the break-off sections (twist-off protrusion 18 and sealing member 15) causing damage to weakened sections (thin-walled portion 24 and thin-walled portion 16) and the consequent loss of sealing performance.
In the known break-off spout such as described in Patent Document 3, the cover (lid member 20) is integral to the spout main body (spout member 10), thereby facilitating production and assembly. However, because the cover (lid member 20) is formed as a single body via the break-off section (sealing member 3), the concern arises that force will be applied to the break-off section (sealing member 3) at the time of assembling the cover (lid member 20), causing damage to weakened section (the connection of sealing member 3 and tube 4) and a resulting loss of sealing performance.
In addition, because a portion of the break-off section (sealing member 3) is exposed outside the cover (lid portion 20), there is concern that external force will be applied directly to the break-off section (sealing member 3) during transport or storage, causing damage to weakened section (the connection of sealing member 3 and tube 4) and a resulting loss of sealing performance.
Further, the concern remains that when external force is applied to the cover (lid member 20), force will be applied via the hinge section (connecting section 5) to the break-off section (sealing member 3), causing damage to the weakened section (the connection of sealing member 3 and tube 4) and a resulting loss of the sealing performance.
Finally, because the break-off sections (protrusion for twist-off 18, sealing member 15, and sealing member 3) are closed off from the start in these known break-off spouts, the problems arise that the spouts are difficult to clean after production and that contents cannot be sufficiently packed into the spout.